Abstract: Using 2 years old azaleas seedlings as test materials, setting up J1 (four kinds of azaleas mycorrhizal fungi), J2 (four kinds of azaleas mycorrhizal fungi and a kind of Pinus massoniana exogenous fungus), J3 (CK) three inoculation ways and with different levels of nutrient elements N, P, K, with Pearson correlation analysis and stepwise regression analysis method of statistics, the correlation between rhizosphere mycorrhizal fungus infection and soil fertility index was analyzed. The results showed that the soil infection rate and nutrient content of the inoculation treatment were significantly higher than that of the non-inoculation treatment. Under each inoculation treatment, the application of N, P, and K nutrients was 1 level (ie, urea 2.2 g, calcium magnesium phosphorus 1.9 g, potassium chloride 1.4 g per plant) could promote the accumulation of soil nutrient content, the application of P, K of 1/4 and N, P, K of 1/2 level under J2 treatment could also promote the accumulation of total nitrogen, available nitrogen and total potassium in the soil. Through correlation analysis, it was found that the infection rate of J1 treatment was positively correlated with total nitrogen content, the infection rate of J2 treatment was extremely significantly positively correlated with available potassium content, and the organic matter and available nitrogen content were significantly positively correlated with J3 treatment. Through stepwise regression analysis, it was found that the main fertility factors influencing the mycorrhizal fungal infection rate of rhododendron seedlings were total nitrogen, available nitrogen and available potassium.

Key words: mycorrhizal fungi, nutrient elements, azalea, rhizosphere

摘要： 以2年生杜鹃(Rhododendron simsii)苗为试材，设置杜鹃花类菌根真菌混合接菌(J1)、杜鹃花类菌根真菌和马尾松外生菌混合接菌(J2)、不接菌(J3)等3种接菌组合以及不同氮磷钾施肥组合试验，结合Pearson相关性分析与逐步回归分析统计方法，分析杜鹃苗根际菌根真菌侵染与土壤肥力指标的相关性。结果表明，接菌处理土壤侵染率和养分含量显著高于不接菌处理，各接菌处理下，施用N、P、K养分为1水平(即尿素2.2 g·株^-1、钙镁磷1.9 g·株^-1、氯化钾1.4 g·株^-1)可以促进土壤养分含量的积累，J2处理下施P、K为1/4水平及N、P、K均为1/2水平也能促进土壤中全氮、有效氮、全钾的积累。相关性分析发现，J1处理侵染率与全氮含量显著正相关，J2处理侵染率与有效钾含量极显著正相关，J3处理与有机质和有效氮含量显著正相关。逐步回归分析表明，影响杜鹃苗菌根真菌侵染率的主要肥力因子是全氮、有效氮和有效钾。

关键词: 菌根真菌, 营养元素, 杜鹃, 根际